Stovepipe construction



Se t. 10, 1940. s. SCHECTER I STOVEPIPE CONSTRUCTION Filed Aug. 5. 1939mlllh I III.

INVENTOR. am J jzec er 2 j i ETORNEY.

Patented Sept. 10, 1940 use STATES anal STOVEPIPE CONSTRUCTION SamuelSchecter, Philadelphia, Pa.

Application August 5,

1 Claim.

The present invention relates to stovepipesin general, and it relatesmore particularly to a novel stovepipe having an improved self-lockinglongitudinal seam.

One of the objects of the present invention is to provide an improvedstovepipe having a more durable longitudinal seam which may be moreeffectively and more securely locked with ease, and which may yet beinexpensively produced.

Other objects of the present invention will ap pear more fully from thefollowing detailed description, accompanying drawing and appended claim.

For the purpose of illustrating the invention, there is shown in theaccompanying drawing one form thereof which is at present preferred,since the same has been found in practice to give satisfactory andreliable results, although it is to be understood that the variousinstrumentalities of which the invention consists can be variouslyarranged and organzied and that the invention is not limited to theprecise arrangement and or zganization of. the instrumentalities asherein shown and described.

Referring to the drawing, wherein like reference characters indicatelike parts,

Figure 1 represents a fragmentary perspective view of a cylindricalblank of sheet metal from which may be formed the improved stovepipe 301forming the subject matter of the present inven- Figure 2 represents aperspective view of an unclosed section of the improved stovepipeconstructed from the blank illustrated in the preceding figure andhaving finished longitudinal marginal portions adapted for engagementwith each other.

Figure 3 represents a fragmentary perspective view of a closed sectionof the stovepipe illustrated in Figure 2, with the longitudinalseammarginal portions thereof being operatively locked together.

Figure 4 represents an enlarged sectional perspective VlEW taken throughan interlocked portion of the stovepipe seam, such as would be seen forinstance on line 44 of Figure 3 looking in the direction of the arrows.

Figure 5 represents an enlarged front elevational view of one of theinterlocking projections marginal portions of the stovepipe.

from a sl1eet-n1etal blank lil bent into cylindrical which are pressedout of one of the longitudinal 1939, Serial No. 2sa4s4 (o1. iss 74)form. The longitudinal marginal portions H and E2 of the blank Eli arerespectively provided at longitudinally spaced intervals withrectangular apertures I3 and cooperating projections l4, pressed,stamped, bent or otherwise formed out of the sheet--metal blank. Theapertures it are spaced somewhat further from the edges of the marginalportion ll than are the projections l4 from the edge of the marginalportion l2, for a reason which will presently appear.

Each of the projections l4 extends radially outwardly, and preferablyextends in a direction away from the adjacent marginal edge of thesheet-metal blank iii. In the particular embodiment illustrated in thedrawing, the projections M each includean inclined generally trapezoidalsurface it so proportioned relative to the rectangular aperture l3 as tofit more or less snugly therein, with the radially outermost edge it ofsaid trapezoidal surface being slightly shorter than the correspondingmajor dimension of the aperture It, to permit ready entry of theprojection M into the aperture l3.

It will be noted that the projection I4 is severed from the sheet metalfrom which it is struck along one free edge It, with the ends of thetrapezoidal surface I 5 being connectedto the sheet metal blank itbymeans of the integral triangular-shaped end-panels I! which are almostperpendicular to the plane of the sheetmetal it. If desired, theprojections l4 may be severed from the sheet-metal along three sides, inlieu of merely along the one side shown. In either case, however, edgeIt constitutes an abrupt well-defined portion which will readily slipinto the recess 3 to lock together the marginal portions l i andl2;separation being prohibited by the edge of projection l4 encounteringthe juxtaposed edge of the aperture l3.

The marginal portion ll containing the apertures i3 is twice folded inupon itself along the fold lines it and I S, to providethe threejuxtaposed plies 29, 2| and 22, with fold l9 not be ing quite as sharpas fold l8, so that the plies 22 and 2| are spaced somewhat furtherapart than are the plies 2i and-20, thereby to provide spacetherebetween for receiving theopposite marginal portion Ill.

The radially-outerrnost ply 2B is preferably oifsetradially outwardlyfrom the body of the stovepipe with the inclined connecting portion 23following as far as possible the curved contour of the underlying foldIll. The radially-innermost ply 22 preferably terminates a substantialdistance beyond the fold [8 in a radially-outwardly offset terminalportion 24 with the inclined connecting portion 25 approximating thecurve of the spaced fold 18.

The opposite projection-bearing marginal portion I2 is offset radiallyinwardly with respect to the body of the stovepipe, with the inclinedintervening portion 26 being bent to fit more or less snugly between thefold it and the radially inwardly spaced inclined portion 25.

After the marginal portions have been bent as above described, theresultant stovepipe resembles that illustrated in Figure 2, with theprojection-receiving apertures l3 being located along the intermediatemarginal ply 2i and being completely concealed by the juxtaposed innerand outer plies 22 and 28, respectively.

The longitudinal marginal portions of the blank I may be readilypermanently interlocked by merely inserting the edge 21 of theright-hand marginal portion l2 intermediate the juxtaposed plies 2| and22 of the left-hand marginal portion II, and then sliding portion l2home, where it assumes the position illustrated in Figure l. During thissliding movement the panels 2i and 22 will be sprung slightly apartuntil the sharp edge l6 of the locking projection M has cleared thetrailing edge of the aperture l3 and the inclined portion 26 has nestedwithin the juxtaposed inclined portion 25, whereupon the plies 2| and 22will spring back substantially to their former positions, snapping theprojections l4 into their cooperating concealed apertures l3.

The resultant longitudinal seam is extremely durable, possessing greatstructural strength, and

the marginal portions forming said seam are permanently interlocked inan extremely effective manner, and Without the presence of visiblesecurement means. Thus, the interlocked marginal portions H and I2 aresecured against separating transverse movement by virtue of the freeedge [6 of the projection l4 abutting the adjacent juxtaposed edge ofthe aperture 53, and relative longitudinal shifting of the interlockedmarginal portions II and I2 is prohibited by the presence of theoutwardly extending triangular end portions H on the projections M,which encounter the immediately adjacent juxtaposed short edges of theapertures I3.

It Will also be noted that when the marginal portions II and I2 areoperatively locked together, the leading edge 21 of the right-handmarginal portion l2 substantially abuts against the fold IQ of theleft-hand marginal portion l I, thereby limiting further movement in aseamclosing direction.

By virtue of the foregoing construction, an improved stovepipe isafiorded wherein movement of the interlocked portions comprising thelongitudinal seam is prohibited in all directions, by juxtaposedwell-defined edges and/or surfaces which cannot slide or work their waypast each other, and all this is achieved in a relatively sim ple andinexpensive manner, and by concealed means which do not project beyondthe seam either interiorly or exteriorly thereof.

The present invention may be embodied in other specific forms Withoutdeparting from the spirit or essential attributes thereof, and it istherefore desired that the present embodiment be considered in allrespects as illustrative and not restrictive, reference being had to theappended claim rather than to the foregoing description to indicate thescope of the invention.

Having thus described the invention, what is hereby claimed as new anddesired to be secured by Letters Patent is:

In a sheet-metal stovepipe having two meeting longitudinal marginalportions, one of which marginal portions is twice folded upon itself toprovide three overlapped plies with the outermost and innermost pliesimperforate, and the other marginal portion projecting between theinnermost and the intermediate of said three overlapped plies, means forlocking said other marginal portion between said innermost and intermediate overlapped plies, said locking means including a plurality oflongitudinally spaced outweirdly-extending projections on said secondmarginal portion terminating in free cut longttudinal edges and beinggenerally elongated and having generally abrupt un-cut end-shoulders,corresponding apertures in said intermediate ply in registration withsaid outwardly extending projections and adapted fully to receive andhouse said projections, said apertures having longitudinal edges ininterlocking relation to the free-cut edges of said projections andhaving end edges in interlocking relation to said end shoulders of saidprojections; said innermost ply and said other marginal portion beingsimilarly offset to form corresponding generally continuous interlockinglongitudinal shoulders.

SAMUEL SCHECTER.

